swhme

I have a 2009 Cayenne GTS w/ the 6MT gearbox. For the past few months, my battery has been draining flat when I'm parked for more than a couple of days. It's been into the shop a couple of times, and here's what they've found:

• The car goes to sleep properly and has a "resting" draw that's very low and well within spec (under 30 milliamps)
• However, every 2-3 hours, it wakes up and the draw spikes significantly for a little while, then goes back down to proper resting state They are struggling to figure out why it's waking up and what's drawing.

Potential Clues:

• My alarm seems VERY sensitive and often goes off as soon as I lock the car. Super annoying. (Is there any way to fully disable the alarm?)
• I replaced the battery a few months ago. New battery is toast now from being drained so often, so it's going to be replaced again.
• Last winter, I tried having a carplay unit from 9xx engineering installed in my head unit. Never got it working properly, and the shop suspected it of causing the draw initially. That unit has been removed and all wiring returned to stock.

Any ideas on where to look? Thank you!

slavie

It must be the "6MT" option. You should trade it with me for my Tiptronic and all your problems will go away.
Ok, just kidding.
Whatever spikes every 2-3 hours may not be the problem, depends on high high the spike and for how long it spikes. If it spikes for 5A for 20-30min, then yea, it's a problem. If it spikes to 2A for 45sec, then no, it's not a problem.
Without actually diagnosing the problem, you're just guessing.

As for your battery, don't rule out a dud battery. I've had brand name batteries that crapped out within 3 months of installation. I, too, was scratching my head and doubting whether it's really the battery - even replaced the alternator once on a Honda as a result. But no, it was just a brand new battery that was bad, and a replacement battery is going strong for years now.

Consider an AGM battery as well, they're more tolerant of being discharged vs traditional batteries.

v10rick

A post about this very problem turned out to be the door actuators firing intermittently, with the alarm set.
The temporary solution was not locking the car.

This could be caused by corroded wiring harness connections under the carpet. Plenty of info on this by searching here and on YouTube.

My GTS did the same when locking the car, just disable the door alert and auto lock settings in the system settings menu (door). Also disable interior alarm.

Capt. Obvious

Have you tried putting the air suspension in jack mode before you park it? My understanding is the car will keep the suspension adjusted even when the car is off. You could have a slow suspension leak that is making the compressor to run while the car is sitting.

hopsis

Air suspension compressor doesn't run without engine running. Instead these is a large pressure bottle in the trunk that is used to lift car if needed when engine is not running.

The original problem with the alarm and battery sounds a lot like a misbehaving door lock switch. It is a common problem in VAG locks.